Mental Capacity Relevant to Victim’s Comparative Fault

The Supreme Court of South Dakota has ruled that in a civil action arising out of the decedent’s death by suicide the jury should have been instructed to “evaluate the effect of [the decedent’s] mental incapacity in judging [the decedent’s] contributory negligence.” Because the jury was instructed to use the typical “reasonable person standard” a verdict for the defendant was reversed.

The Court cited with approval the following language from the North Dakota instructions: “If the patient’s capacity for self care is so diminished by mental illness that it is lacking, we agree that an allocation of fault is not appropriate. . . In making the fault comparison, the factfinder should always take into account the extent of the patient’s diminished mental capacity to care for his own safety.”